How to open a file on read only mode on linux?
This command has been tested on Redhat Enterprise linux 6 (RHEL6) server. To open the file with vim in read only mode on linux, you need to run “vim -R” as below. Vim is enhanced version of vi editor that viewing the text file with coloring. “vim -R” is good command if you want to avoid accidentally deleted any important line as in read only.
[root@rhel6 ~]# vim -R /etc/passwd